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BUG: KMSAN: kernel-infoleak in __copy_to_user include/linux/uaccess.h:121 [inline]
BUG: KMSAN: kernel-infoleak in __kvm_write_guest_page+0x2e1/0x490 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1855
CPU: 1 PID: 27265 Comm: syz-executor4 Not tainted 4.20.0-rc7+ #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
 kmsan_internal_check_memory+0x9d4/0xb00 mm/kmsan/kmsan.c:704
 kmsan_copy_to_user+0xab/0xc0 mm/kmsan/kmsan_hooks.c:601
 __copy_to_user include/linux/uaccess.h:121 [inline]
 __kvm_write_guest_page+0x2e1/0x490 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1855
 kvm_vcpu_write_guest_page arch/x86/kvm/../../../virt/kvm/kvm_main.c:1876 [inline]
 kvm_vcpu_write_guest+0x77a/0x920 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1910
 kvm_write_guest_virt_helper arch/x86/kvm/x86.c:5086 [inline]
 emulator_write_std+0x391/0x4d0 arch/x86/kvm/x86.c:5110
 segmented_write_std arch/x86/kvm/emulate.c:853 [inline]
 em_fxsave+0x7c2/0x840 arch/x86/kvm/emulate.c:4073
 x86_emulate_insn+0x2d1c/0xb3e0 arch/x86/kvm/emulate.c:5601
 x86_emulate_instruction+0x1105/0x73b0 arch/x86/kvm/x86.c:6367
 kvm_mmu_page_fault+0xcef/0x2860 arch/x86/kvm/mmu.c:5351
 handle_ept_violation+0x565/0x5a0 arch/x86/kvm/vmx.c:7720
 vmx_handle_exit+0x1582/0x9a00 arch/x86/kvm/vmx.c:10632
 vcpu_enter_guest arch/x86/kvm/x86.c:7811 [inline]
 vcpu_run arch/x86/kvm/x86.c:7874 [inline]
 kvm_arch_vcpu_ioctl_run+0xa5ad/0x11400 arch/x86/kvm/x86.c:8074
 kvm_vcpu_ioctl+0xfe9/0x1d20 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596
 do_vfs_ioctl+0xeeb/0x2c80 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x4579b9
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd59bedac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004579b9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd59bedb6d4
R13: 00000000004c0a77 R14: 00000000004d22b0 R15: 00000000ffffffff

Local variable description: ----fx_state@em_fxsave
Variable was created at:
 em_fxsave+0xcb/0x840 arch/x86/kvm/emulate.c:4060
 x86_emulate_insn+0x2d1c/0xb3e0 arch/x86/kvm/emulate.c:5601

Bytes 8-159 of 160 are uninitialized
Memory access of size 160 starts at ffff8881ef3bed90
Data copied to user address 0000000020000000
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